The present invention relates to sampling tubes and, more particularly, to sampling tubes adapted for obtaining samples of liquid containing frazil ice.
Obtaining samples of frazil ice for research and analysis into its effect on, for example, hydroelectric power plants, has presented a number of problems. Most of these problems arise due to the failure to provide a liquid sampler which can quickly obtain a sample which contains a true representation of the frazil ice in the area being analyzed.
Sampling devices such as disclosed in U.S. Pats. Nos. 3,504,550; 3,807,234; 2,515,882; 2,436,737 and 892,944 comprise hollow cylindrical samplers initially open at both top and bottom which are lowered to the desired depth whereupon the bottom of the sample tube is closed and the entire unit raised to the surface.
For collecting frazil ice samples, the apparatus disclosed in the above noted patents fail to collect total samples representative of the area. In an attempt to obtain satisfactory samples, it has been necessary at times to chop large diameter holes in the ice to allow a diver to go under the ice and sample from the bottom up.